Device for driving films in cinematiographic projectors



INVENTOR ATTORNE w. GUGGER Feb. 16, 1954 DEVICE FOR DRIVING FILMS IN CINEMATOGRAPHIC PROJECTORS Filed June 21, 1950 Patented Feb. 16, 1954 DEVICE FOR DRIVING FILMS IN CINEMATO- GRAPHIC PB OJ ECTORS Walter Gugger, Yverdon, Switzerland, assignor to Paillard S. A., a corporation of Switzerland Application June 21, 1950, Serial No. 169,395

Claims priority, application Switzerland July 15, 1949 6 Claims.

' Devices for driving and guiding a film in a cinematographic projector are already known, which are constituted by members mounted in a removable manner, which enables them to be replaced by others, allowing of the projection in the same apparatus of films of different sizes. The said members are in principle the shutter, the presser channel, the sprocket wheel and their claws, that is to say the support of the guide rollers co-operating therewith. The shutter and the presser channel are essentially guide memers.

In the known driving devices with interchangeable members, the sprocket wheel'is generally held in the operating position on its spindle, by means of a milled nut which must be unscrewed and; screwed up during changing. Time is lost by the operator, whilst there is also a risk of damaging the threads of the spindle and nut in the course of time, the change not always being carried out under good con ditions of lighting. Similar difficulties and inconveniences also exist in connection with the changing of the claws of the sprocket wheel, that is to say in connection with the guide rollers co-operating therewith.

The present invention relates to a device for driving a film in a cinematographic projector provided with a sprocket wheel with the support for the guide rollers co-operating therewith.

The invention has for its object to obviate the above mentioned disadvantages by the fact that the sprocket wheel is provided with a locking member with a spring co-operating with a recess of its spindle, so as to retain it automatically on the latter in the operative position, the support being mounted in a sliding manner on guides of the wall of the apparatus and provided with at least two openings allowing of the release of the said guides by placing the latter opposite the former and moving it perpendicularly to its plane of sliding.

One form of construction of the subject of the invention is shown by way of example in the accompanying drawings wherein:

Fig. 1 is a section on the line I-I of Fig. 3.

Fig. 2 is a section on the line 11-11 of Fig. 3, the sprocket wheel being removed.

Fig. 3 is a front view of the support for the guide rollers, with its securing means.

The spindle l of the sprocket wheel 2 turns in a bearing 3 in the wall 4 of the apparatus. The end 5 of the spindle I which projects to the outside, carries a coupling member formed by a Washer 6 secured thereto by a pin. The washer is provided with two teeth 1 adapted to penetrate 2 into two corresponding recesses 8 of the body of the sprocket wheel, located on opposite sides of its bore 9 into which penetrates the end 5 of the spindle,

This end is provided with a circular groove ID co-operating with a spring catch formed by a ball ii urged by a spring l2 in a radial seating of the body of the sprocket wheel. As will be seen in Fig. 1, the central plane of the groove l0 does not correspond with the central plane of the catch, so that the ball H bears against the front edge 13 of the groove and applies, by the action of the spring l2, an axial thrust on the body of the sprocket-wheel, pushing the latter against the washer 6, that is to say ensuring automatically the engagement of the members 1 and 8 forming the claw coupling of the sprocketwheel.

For the setting in position and the removal of the sprocket-wheel 2, it suffices to move it axially on the end 5 of the spindle l for engaging the catch II with the groove It or for disengaging it therefrom.

The support for guide rollers M or claw of the sprocket-wheel is formed by a body l5 provided with a lug l6 and with a cylindrical wall I! located opposite the body of the sprocketwheel 2.

The support is mounted in a sliding manner on the wall 4 of the apparatus by means of two headed screws I8.

The lug I6 is provided with two guide portions (9 sliding on the heads of the screws 18. It is also provided with an opening 20 in its central portion for the passage of the spindle 5 and of the washer 6 which it carries. The opening 20 is connected to the two guide portions [9. One of these is also connected to an opening 2| adapted to permit of the passage of the head of one of the screws l8.

To the opening 20 are also connected two recesses 22 and 23 co-operating with spring catches 24 and 25 formed by spring urged balls.

The arrangement of the recesses 22, 23 and of the catches 24, 25 is such that when the catch 25 engages with the recess 23, the rollers M are disengaged from the sprocket-wheel 2 and enable the film to be placed in position or removed. When the recess 22 engages with the catch 24, they are in contact with the supply device, in the operative position.

These two positions, well defined by the action of the catches 24, 25 are obtained simply by sliding the guides l9 on the bearing surface of the screws [8.

For withdrawing and replacing the support [5, the sprocket wheel 2 is first removed from its spindle and the support 55 is pushed from the bottom upwards (Fig. 2) against the action of the catch 25, until the head of the lower screw 18 is opposite the opening 2|. The head of the upper screw I8 is then opposite the opening 20..

It is then possible to remove the support l5 by moving it in the direction ofthe spindle: 5; The placing in position takes place in a similar manner, the operations being carried out in the opposite direction.

It is to be noted that it is impossible to remove the support I5 as long as the sprocket wheel is on its spindle 5, the guide rollers 14 engaging the sprocket wheel 2 and thereby obstructing a displacement n cessary for bringing the screws H3 in registry with opening 20 or 2| respectively.

I claim:

' 1.. A device for driving a film in. a cinematographic projector, comprising, a stationary wall, arspindle journaled' in the wall, a sprocket wheel mounted on the spindle, means coupling the sprocketwheel to the spindle for rotation therewith. guide roliers guiding the film toward the sprocket wheel, a support supporting the rollers adjacent the sprocket Wheel and including a slotted part extending at right angles to the rollers, saidislotted part, having slots each embodying a wide and a narrow portion, retaining elements fixed in the wall and each including a head spaced from the wall and on motion of the support part toward the wall passing through a wide slot portion and being larger than a narrower slot: portion, the length of each slot'requiring a element, the mounting of. the support on the wall'requiring a motionof thesupport toward the wall and another motion parallel thereto,

3:; Device according to; claim land wherein the spindle has an annular groove with an inclined side remote from the wall and also com- 4 prising a spring urged ball seated in the sprocket wheel and solely engaging the inclined groove side to thereby push the sprocket wheel toward the wall and. to maintain. it inworking position.

4. Deviceaccording to claim .3 and wherein the coupling means comprises teeth and the sprocket wheel has recesses receiving the teeth and the ball maintains the teeth in the recesses.

5". A device for driving a film in a cinematographic projector, comprising a stationary Wall, a spindle journaled in the wall, a sprocket mounted on the spindle means coupling the sprocket to the spindle for rotation therewith, guide rollers guiding the film toward the sprocket, a support supporting the rollers adjacent the sprocket and including a slotted plate part extending at right angles to the rollers, said slotted plate part having slots each embodying a wide and a narrow portion retaining screws fixed in the wall and each having a head spaced from. and on. motion. of the support plate toward the-wall passingthroughw a wide slot portion. and being larger thaniatnare rowslot portion, the length of each slot'requiring a motion of the support plate parallelrtcr the? wall to a. position registering each screw head withitswide slot portion of greaterdistanceithan that of the possible motion of the rollerssto' e1r-= gage the sprocket.

6. The device of claim .5 and wherein the-sup.- port plate has an opening; forreceiving: the sprocket spindle and two holes and also compris ing apair of balls seated in the: wall and each partly received in a plate hole when the: plate is:

retained onthe wall.

WALTER. GUGGER...

References Cited in the file of thisrpatentr UNITED STATESPATENTS" Germany July 20, I936 

